Electromagnetic actuating apparatus for clockwork mechanisms

ABSTRACT

THE INVENTION RELATES TO AN ELECTROMAGNETIC ACTUATING APPARATUS IN WHICH AN ARMATURE IS ATTACHED BY AN ELECTROMAGNET WHEN CURRENT IS SWITCHED ON. THIS KIND OF APPARATUS IS EMPLOYED FOR ACTUATING ELECTRIC SWITCHES, SUCH AS CLOCKWORK WINDERS OR THE LIKE. THE ARMATURE ROLLS UPON THE POLE PIECE IN A MANNER SO AS TO REDUCE NOISE OF OPERATION AND THE ARMATURE COMPRISES AN OPERATIVE ELECTRICAL CIRCUIT FROM A BATTERY TO THE ELCTROMAGNET THROUGH AT LEAST A PORTION OF THE APPARATUS.

Feb. 16, 1971 A. KREIDLER 3,563,026

ELECTOMAGNETIC ACTUATING APPARATUS FOR CLOCKWORK MECHANISMS original Filed June*15, 1967 United States Patent AO 3,563,026 ELECTROMAGNETIC ACTUATING APPARATUS FOR CLOCKWORK MECHANISMS Alfred Kreidler, Zurich, Switzerland, assignor to Metall-Invent S.A., Zug, Switzerland Original application June 15, 1967, Ser. No. 646,287, now

Patent No. 3,477,049. Divided and this application Sept. 19, 1969, Ser. No. 859,262

Int. Cl. G04c 1/00 U.S. Cl. 58--41 4 Claims ABSTRACT OF THE DISCLOSURE The invention relates to an electromagnetic actuating apparatus in which an armature is attracted by an electromagnet when current is switched on. This kind of apparatus is employed for actuating electric switches, such as clockwork winders or the like. The armature rolls upon the pole piece in a manner so as to reduce noise of operation and the armature completes an operative electrical circuit from a battery to the electromagnet through at least a portion of the apparatus.

This invention relates to an electromagnet actuating apparatus for clockwork mechanisms in which an armature is attracted by an electromagnet when current is switched on. This kind of apparatus is employed for actuating electric switches, such as clockwork winders or the like.

This application is a division of application Ser. No. 646,287 iled June l5, 1967, now Pat. No. 3,477,049 for Electromagnetic Actuating Apparatus, the armature and pole pieces having corresponding surfaces in continuous rolling contact.

Striking of the armature upon the pole pieces of an electromagnet results in a brief impact noise which is undesirable in many cases. Various measures are known Whose purpose is to eliminate or at least to reduce the aforementioned impact noise. It has been proposed to dispose an intermediate layer of damping material, such as foam rubber, between the armature and the pole piece. Quite apart from the fact that such measures can only reduced but not completely eliminate the noise, such damping suffers from the disadvantage of substantially weakening the force effect of the magnet because, owing to the presence of the damping material, a gap of considerable size remains between the armature and pole piece. It is also known to swing the armature past the pole piece of the electromagnet perpendicularly to its axis. Although this procedure is completely free of noise, it necessitates an air gap of considerable size between armature and pole piece which in turn results in a considerable deterioration of the force effect.

The invention provides a remedy and enables the deliberate striking noise to be entirely avoided without incurring any new disadvantages. The solution to the problem is obtained in an electromagnetic actuating apparatus of the ykind heretofore described by constructing the armature as a member which rolls upon the pole piece of the electromagnet. It is appropriate for the armature and pole piece to be in physical contact in the quiescent condition at the starting position of the rolling motion.

Still further object of this invention reside in the provision of an electromagnetic actuating apparatus for clockwork mechanisms that is simple in construction, employs electrical and mechanical circuitry which use a ratchet mechanism for completing electrical circuits, and which is efficient in operation.

These, together with the various ancillary objects and features of this invention, which will become apparatus as the following description proceeds, are attained by this electromagnetic actuating apparatus for clockwork mechanisms, preferred embodiments of which are illustrated in the accompanying drawing, by way of example only, wherein:

The ligure is a schematic illustration of an embodiment of the invention employing a solenoid core with a convex end face, a straight armature, and a clock Winder mechanism.

With continuing reference to the accompanying drawings, reference numeral 1 designates the solenoid core of a cup magnet. The solenoid core is disposed centrally in a cup structure 2 and is joined to its base. The cup 2 and core 1 are constructed of magnetizable material, mainly soft iron. A winding 3 in the cup surrounds the solenoid core 1.

The pole piece 13 formed by the end face of the cup 2 together with the end face of the solenoid core 1 is constructed in a convex shape. The armature 12 on the other hand is straight. It is retained in its initial or starting position by a tension spring 6 while touching the pole piece 13 at a tangential position 7 and bearing on its other side upon a stop 8. A further stop 9 limits the rolling motion resulting from the magnet action in the attracted position of the armature 12. A contact roll 54 for the mechanism to be actuated is provided at that end of the armature 12 which faces away from the operating position of the tension spring `6.

The contact roll 54 cooperates with the tensioning lever 55 which swivels about a shaft 56 of the ratchet gear 57. Tensioning lever 55 carries at one end thereof a ywheel mass 58 and at its other end a pawl 59 which is provided with a leaf spring 60 and engages the teeth 61 of the ratchet gear 57. A rigidly mounted stop 62 limits the swinging movement of tensioning lever 55 which is engaged by clock spring 63. The clock spring is shown diagrammatically as a helical tensioning spring for the sake of simplicity. The clockwork proper is indicated schematically by circles 64 and 65, A battery 66 is connected with the coil 3 of the magnet through the conductor lead 67. Armature 12 is electrically connected through lead 68 and tensioning spring `6 and through contact roll 54 conductively engaging tension lever 55 in the position shown: The circuit to the battery 66 is closed over the clock spring 63 and conductor lead 69.

At the location shown, the electromagnet coil 3 is supplied with current, the armature 12 is wound and the tensioning lever 55 swivels over roll 54 of the armature in the direction of arrow a thereby tensioning clock spring 63. When armature 12 comes to a standstill in the position shown in phantom lines, the tensioning lever -55 still moves by a certain angle as a result of the inertia of its flywheel mass 58 until it stops at the stop 62 indicated by the phantom line position of tensioning lever 55. In this position pawl 59 engages the teeth 61 of the wheel 57, thereby coupling the tensioned clock spring 63 with the clock work 64, 65. As soon as the tensioning lever 55 has left contact roll 54, the magnet coil 3 becomes currentless. The armature 12 is brought back by means of spring 6 into starting position and it remains there until the clockwork 64, 65 driven by spring 63 has run down and the tensioning lever 55 against runs up against roll 54. With the current connection thus restored, the aforedescribed operation is repeated.

A latitude of modification, substitution and change is intended in the foregoing disclosure, and in some instances, some features of the invention will be employed without a corresponding use of other features.

I claim:

1. An electromagnetic actuating apparatus comprising an electromagnetic including a solenoid core provided with a convex pole piece, a movable straight armature, said armature and said pole piece having corresponding surfaces in continuous rolling contact, a clock Winder mechanism having a clock-spring, a tensioning lever hav- `ing ratchet means thereon, said clock-spring being attached to said lever, said armature being engageable with said lever, and electric circuit means for completing an operative electrical circuit to said electromagnet when said armature engages said lever.

2. An electromagnetic actuating apparatus comprising an electromagnet including a solenoid core provided with a pole piece, and a movable armature, said armature and said pole piece having corresponding surfaces in continuous roller contact, a clock Winder mechanism having a clock spring, a tensioning lever having ratchet means thereon, said clock spring being attached to said lever, said armature being engageable with said lever, and electric circuit means for completing an operative electrical 4 circuit to said electromagnet when Said armature engages said lever.

3. An apparatus according to claim 2, including means for resetting said armature connected thereto.

4. An apparatus according to claim 3, wherein said armature and said pole piece are in physical contact in the static condition at the starting position of said continuous rolling Contact.

References Cited UNITED STATES PATENTS 2,120,178 6/1938 Hausrath 335--270 FOREIGN PATENTS 621,121 9/1926 France 58-41 RICHARD B. WILKINSON, Primary Examiner E. C. SIMMONS, Assistant Examiner U.S. C1. XR. 335--276 

